[LAA] Remove unneeded findValue calls (NFC).

Use findLeader directly instead if going through findValue,
getLeaderValue. This is simpler and more efficient.

Author: fhahn

llvm/lib/Analysis/LoopAccessAnalysis.cpp

@@ -520,14 +520,13 @@ void RuntimePointerChecking::groupChecks(
                                            Pointers[I].IsWritePtr);
 
     SmallVector<RuntimeCheckingPtrGroup, 2> Groups;
-    auto LeaderI = DepCands.findValue(DepCands.getLeaderValue(Access));
 
     // Because DepCands is constructed by visiting accesses in the order in
     // which they appear in alias sets (which is deterministic) and the
     // iteration order within an equivalence class member is only dependent on
     // the order in which unions and insertions are performed on the
     // equivalence class, the iteration order is deterministic.
-    for (auto MI = DepCands.member_begin(LeaderI), ME = DepCands.member_end();
+    for (auto MI = DepCands.findLeader(Access), ME = DepCands.member_end();
          MI != ME; ++MI) {
       auto PointerI = PositionMap.find(MI->getPointer());
       assert(PointerI != PositionMap.end() &&
@@ -2264,13 +2263,9 @@ bool MemoryDepChecker::areDepsSafe(const DepCandidates &AccessSets,
     if (Visited.count(CurAccess))
       continue;
 
-    // Get the relevant memory access set.
-    EquivalenceClasses<MemAccessInfo>::iterator I =
-      AccessSets.findValue(AccessSets.getLeaderValue(CurAccess));
-
     // Check accesses within this set.
     EquivalenceClasses<MemAccessInfo>::member_iterator AI =
-        AccessSets.member_begin(I);
+        AccessSets.findLeader(CurAccess);
     EquivalenceClasses<MemAccessInfo>::member_iterator AE =
         AccessSets.member_end();